using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Example
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();


            CommandBinding cbinding = new CommandBinding(MainWindow.GetButtonContentCmd);
            cbinding.Executed += Cbinding_Executed;
            cbinding.CanExecute += Cbinding_CanExecute;
            this.CommandBindings.Add(cbinding);

            this.textCommand.OnCanExecute = (obj) => true;
            this.textCommand.OnExecute += TextCommand_OnExecute;
            this.butCustom.Command = this.textCommand;
        }

        private void TextCommand_OnExecute(object? obj)
        {
            MessageBox.Show("自这义命令被调用！");
        }

        private void Cbinding_CanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = true;
        }

        private void Cbinding_Executed(object sender, ExecutedRoutedEventArgs e)
        {
            MessageBox.Show(e.Source.ToString());
        }

        public static RoutedCommand GetButtonContentCmd = new RoutedCommand();

        public CustomCommand textCommand = new CustomCommand();

        public class CustomCommand : ICommand
        {
            public string? Command { get; set; }
            public CustomCommand() { }
            public CustomCommand(string command, Action<object?>? onExecute = null, Func<object?, bool>? onCanExecute = null)
            {
                this.Command = command;
                this.OnExecute = onExecute;
                this.OnCanExecute = onCanExecute;
            }
            public event EventHandler? CanExecuteChanged;

            public event Action<object?>? OnExecute;
            public Func<object?, bool>? OnCanExecute;

            public bool CanExecute(object? parameter)
            {
                if (this.OnCanExecute != null) return this.OnCanExecute(parameter);
                else if (this.Execute != null) return true;
                else
                {
                    this.CanExecuteChanged?.Invoke(this, new EventArgs());
                    return false;
                }
            }

            public void Execute(object? parameter)
            {
                this.OnExecute?.Invoke(parameter);
            }
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            new CustomWindow().Show();
        }
    }
}